Turbulence means for radiator tubes



- Oct. 19, 1937. F. M. YOUNG 2,096,272

TURBULENCE MEANS FOR RADIATOR TUBES Filed July 15, 1955 //Y nay-r02 Patented a. 19, 1937 UNITED STATES PATENT OFFICE Fred M. Young, Racine, Wis., assignorto Young Radiator Company, Racine, Wis.

' Application July 15, 1935, Serial No. 31,418

6 Claims.

vices, for various reasons, flattened or oval tubes have been found more desirable than round tubes. With either it is customary to supply closely spaced fins through which the tubes extend and are intimately associated, thus to increase the air contact surface.

Means on the tube fins are frequently provided to cause air turbulence. The present invention provides means for causing turbulence of the liquid as it passes through the tubes.

Low heat transfer eiliclency is 0 used by skin friction which causes a very slow movement'of the thin layer of liquid that is .in direct contact with the inner walls of the tubes. The liquid in the center of the tubesmay travel rapidly through the tube; however heat transfer must necessarily be through this slowly moving film of liquid to the tube surface.

2 I provide means whereby all of the liquid is caused to closely wipe the tube surface at frequent intervals, thus to break up the surface film and more readily transfer temperature from the main body of the liquid to the tube.

25 I accomplish these results' by means of a centrally positioned thin metal strip having edges which contact the walls of the tubes and having suitably positioned embossments or projections thereon, whereby the liquid will be diverted in 30 spots and crowded against the -wallsof the tubes, thus to breakup the flow and mix the. liquid and cause it to closely wipe the tube surface at frequent intervals. It will be understood that some temperature 35 transfer will also take place through the central strip to the walls of the tubes, at its contact therewith. A I To these and other useful ends this invention consistsofmatter hereinafter set forth and 40 claimed and shown in the accompanying drawing in which:

Figure 1 is a longitudinal transverse sectional view of a flat radiator-tube showing a fraction of 45 the usual tube header, illustrating one form of my tube strip in position.

Figure 2 is a transverse sectional view of the device shown in. Figure 1. taken on line 2 of Figure 1.

5o Flgure3 is a side view of a fraction of my metal strip as shown in Figures 1 and 2.

Figure 4 is a sectional view of a tube and metal strip illustrating a means to more closely center the strip in the tube.

55 Figure 5 is a longitudinal transverse fractional (Cl. 138-38) In conventional radiators 'or heat transfer deview of the device shown in Figure 4, taken on line 5 of Figure 4.

Figure 6 illustrates a modification. f Figure 7 is a transverse sectional view of an elliptical tube equippedwith one form of my in- 5 vention.

' .As thus illustrated in Figures 1, 2 and 3 the radiator tube is designated by reference numeral l0 and a. fraction of a tube plate by numeral ii. My improved tube strip'in its entirety, is desig- 10 nated by numeral I3. I provide embossments l4 and I5, each being of a suitable height so as to nearly contact the tube walls at the apex of the embossments. These embossments are preferably alternately positioned and in rows pn the 15 opposite sides of the strip. Forexample, embossments l4 form a row on one side of the strip and embossments i5 are positioned in a row on the otherside of strip l3, embossment I5 projecting in the opposite direction to embossment l4 and 'altemately spaced.

I may however, elect to position embossments I5 directly opposite embossments M; or the embossments on one side of the strip may be directed oppositely or alternately so that adjacent-embossments are directed oppositely. Thus when the liquid is diverted and displaced by embossment l4, embossment l5 will tend to displace an equal quantity of liquid and re-divert the cross flow of liquid in the opposte direction. Clearly it will be seen that while the liquid will, at intervals, be crowded against the walls of the tubes, it will also be split or spread transversely, only to be again diverted, split and spread oppositely; thus turbulence will be set up which will not onlycause the liquid to closely wipe the tube walls at frequent intervals as it passes through the tube, but it will also be diverted and divided at frequent intervals, whereby it will be thoroughly mixed so as to present the maximum and uniform temperature for wall contact.

- Clearly the strip i3 and its embossments are at all times in intimate contact with the passing liquid and since the strip edges contact with the tube walls, some temperature change takes place between the liquid and tubes through the strips.

It will be understood that the embossments may be variously positioned and shaped or the diverting means may be other than circular in shape. Y

In Figures 4 and 5 I illustrate the embossments as having very small supplemental embossments or projections II, adapted to contact the tube wall whereby the strip 21 will be held in a central podtion and another heat transfer means proor they can be made oblong in a transverse direction or otherwise shaped for the purpose herebefore outlined. I provide curved portions 28 on both edges of strip 25 whereby the strip will be caused to yieldingly contact the tube and form a larger contact surface for reasons which will be,

apparent.

In Figure 7 I illustrate my improvement adapted to serve preferably, an oval tube 30 having a strip 3| as in the other designs. In this design the projections 32 and 33are formed as illustrated and positioned in the center of the strip or otherwise and alternately on opposite sides thereof. These projections will cause the liquid to impinge the walls of the'tube alternately.

Clearly applicant's device may be used to advantage on any kind of heattransfer cores and for this reason it has not been shown as associated with any particular design of core. It will be understood that the embossments may be variously shaped and positioned, therefore many minor changes may be made without departing from the spirit and scope of thisinvention.

Having thus shown and described my. invention, I claim:

1. A radiator tubeoi the class described, having means to cause turbulence in the liquid-passing therethrough, said tube having a flattened shape in cross section, said means comprising a metal strip adapted to.be held midway between the side walls of said tube and having a number of spaced spherically shaped embossmlents positioned alternately on opposite sides t ereof.

2. A radiator tube o'f the class described, having means to cause turbulence in the liquid passing therethrough, said tube having an elliptical shape in cross section, said means comprising a metal strip adapted to be held midway between the side walls of said tube and having a number of spaced spherically shaped embossments positioned alternately on opposite sides thereof.

3. A radiator tube of the class described, having means to cause turbulence in the liquid passing therethrough, said tube being elongated in cross,

section, said means comprising a metal strip adapted to be held midway the side walls of said tube and having a number of spaced spherically shaped embossments whereby the passing fluid will be directed at intervals against the side walls of said tube, said embossments being positoned alternately on opposite sides of said strip.

4. A tube of the class described, having means therein to cause turbulence in the liquid or gas passing therethrough, said means comprising a metal strip adapted to be held midway in said tube and having a number of spaced apart bulging embossments each adapted to force the passing liquid or gas to impinge the wall of said tube, said embossments positioned alternately on opposite sides of said strip.

5. A heat transfer tube of the class described, comprising means therein 'to cause turbulence of the gas or liquid passing therethrough, said means comprising a metal strip having a number of spaced apart embossments formed therein alternately on opposite sides and edges and adapted to cause the passing liquid or gas to closely impinge the walls of the tube at spaced intervals, said embossments being formed by pressing the material into bulged raises.

. 6. A radiator tube of the class described, said tube having a flattened shape in cross section and a metal strip positioned therein. said strip having alternately positioned spaced apart 'embossments on opposite sides thereof, relatively small projections formed bn the apex of said embossments which are adapted to contact the walls of said tube and hold said strip in a'central position therebetween.

FRED M. YOUNG. 

